The level of performance of an elevator system is a function of a number of parameters. Among these parameters is the extent to which passengers and prospective passengers of the elevator system are happy with the service they receive from the elevators. This, in turn, is a function of a number of parameters, many of them relating to the amount of time that the passenger spends waiting to be delivered to his destination. This time spent waiting is, in turn, a function of a number of time-based parameters. One of these time-based parameters is the waiting time, that is, the amount of time from when a hall call button is pushed to when the elevator arrives. Another time-based parameter is the ride time between when the elevator car leaves the floor or a hall call button is pushed to the time when the car arrives at the destination floor of the passenger. Between a) the time that the elevator car arrives at the floor to receive the passenger who has pressed a hall call button and b) the time when the elevator car leaves is c) time spent opening elevator doors, holding the doors open so that the passenger can enter and closing the doors. The time spent holding the elevator doors open so that the passenger can enter is called the door dwell time. The door dwell time is typically a fixed quantity which is large to accommodate the great length of time required for a slow-moving passenger or a group of passengers to enter the car. Where a fast-moving passenger quickly enters the car from the hall, that passenger as well as all the passengers already in the car is forced to wait for the elevator door dwell time associated with a slow moving passenger to expire. Thus, this fast-moving passenger has an unnecessarily long waiting time because the door dwell time is fixed to a value suitable to some other slow moving passenger.
In addition, the amount of time that the passenger spends waiting to be delivered to his destination is a function of the efficiency of the elevator dispatching system which is in turn a function of the amount of passenger traffic known to the dispatching system.